The increasing prevalence of chronic disease in the aging U.S. population presents substantial challenges to delivering medical care that is both patient-centered and consistent with evidence-based guidelines. Dr. Boyd's prior work demonstrated that the application of disease-specific guidelines to older patients with multimorbidity is limited by the complexity, expense, and burden ofthe recommended therapeutic regimens and monitoring requirements. Optimal care for our aging society entails the development of practical evidence-based treatment models for medically-complex older patients that permit flexible goal-setting according to patient preferences and perceived treatment burden. The overall goal of this project is therefore to develop a practical tool for assessing treatment burden among older patients with multimorbidity, to assist in medical decision making. Toward this end, Dr. Boyd proposes to study older individuals with an index diagnosis of diabetes in combination with other comorbid conditions as a model for examining treatment burden in multimorbidity. We propose to characterize the domains and moderators of treatment burden in this population via a secondary analysis of data from the Guided Care project, a study of older adults with multi-morbidity (Aim 1), as well as through a series of focus groups (aim 2). We will synthesize these data and data from the literature to develop a clinically practical measure of treatment burden (Aim 3), and, finally, we will pilot test this instrument in a clinical setting (Aim 4), as preparation for an ROl study to evaluate the clinical utility of the instrument for improving patient adherence and outcomes for a broader population of patients with multi-morbidity. This work will provide the foundation for a clinical research career focused on improving decision making and outcomes for older people with multimorbidity. Dr. Boyd aims to become an independent clinical investigator dedicated to improving care for older people with multimorbidity. In concert with her sponsors, Dr. Boyd has charted a research path that is a direct extension of her prior work, and will be conducted within a structured career development plan that includes coursework, mentoring, and a multidisciplinary research advisory committee. RELEVANCE (See instructions): Many older adults have multiple co-existing conditions, but it is not known how to best manage these conditions simultaneously. Dr. Boyd aims to improve clinical decision-making and outcomes for older people with multimorbidity.